The Gale Encyclopedia of Neurological Disorders vol 1 - part 4 docx

Neuopathy Disease or disorder, especially a degenerative one, that affects the nervous system Vasculitis Inflammation of the blood vessels • herpes simplex virus infections A pathergy test is a skin-prick test to see if a red bump will form at the injection site If there is a reaction, the test is positive This test may be given to patients suspected of BD, but it is not an indicator for the disease Only a small percentage of patients diagnosed with BD actually test positive • frequent infections of Streptococcus bacteria • environmental factors The four primary symptoms of BD are recurring complications that rarely present simultaneously These include: • Oral ulcers (aphthous ulcers) Usually the first sign of disease, these sores resemble common canker sores, but are present in greater number, larger size, and occur more frequently They may be painful and persist for up to two weeks • Genital ulcers Similar in appearance to oral ulcers, genital sores typically occur on the scrotum in males and in the vulva in females These ulcers are painful • Ocular inflammation (uveitis) May affect the front of or behind the eye, or both together Inflammation of the middle eye area leads to blurred vision, light sensitivity, and possibly loss of sight • Arthritis Temporary inflammation of the joints develops intermittently A large number of secondary symptoms are also associated with BD These affect the following areas: • Skin Acne-like outbreaks of red skin sores develop on the legs and parts of the upper body • Vascular system Formation of blood clots may lead to aneurysms or inflammation of veins (thrombosis) This is more frequent in men • Gastrointestinal system Less often, patients may develop ulcers along the digestive tract • Central nervous system Inflammation of the blood vessels in the brain can result in a variety of conditions such as headache, confusion, stroke, or seizures Treatment team Patients diagnosed with Behỗet disease require a diverse treatment team due to the variety of symptoms and complications The primary specialist is usually a physician who specializes in arthritis (rheumatologist) In addition, the team includes a dermatologist (skin), an ophthalmologist (eyes), a gynecologist or urologist (genital), a gastroenterologist (digestive system), and a neurologist (nervous system) Treatment Treatment is focused on the symptoms Several medications are available to minimize discomfort caused by these symptoms Most treatment efforts attempt to reduce pain and inflammation Corticosteroids such as Prednisone are prescribed since they are effective at regulating inflammatory responses These may be administered as injections, pills, or creams Immunosuppresant drugs such as cyclosporine, azathioprine or cyclophosphamide help suppress the immune system’s response to a less-active state Both corticosteroids and immunosuppresants can have serious side effects Patients must be closely monitored by a physician while using these medications The use of interferon alpha 2a and 2b has been an effective treatment for ulcers and arthritis in patients who were less responsive to standard treatment regimens Thalidomide has also shown potential as a treatment for BD A complication of thalidomide is neuropathy Thalidomide should not be used by women since it causes severe birth defects in fetuses Recovery and rehabilitation Diagnosis Behỗet disease is diagnosed based on a set of guidelines established by an international group of physicians A physician observes clinical signs and symptoms during patient examination The most recent and accepted guidelines for a positive diagnosis include the presence of recurring oral ulcers (three or more times in one year) and Unlike most diseases, BD has symptoms that periodically flare up and then disappear for a period of time As a result, patients may have long intervals with no complications After treatment for active symptoms, patients usually require rest due to fatigue Moderate exercise is also recommended to improve circulation and muscle strength GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 143 Behỗet disease Key Terms at least two of four secondary symptoms, including recurring genital ulcers, uveitis, skin lesions, a positive pathergy test Bell’s palsy Clinical trials As of early 2004, the National Eye Institute was sponsoring two studies and recruiting patients with Behỗet disease Evaluation and Treatment of Patients with Inflammatory Eye Diseases” (study number 000204) evaluates patients with inflammatory eye diseases and the success of current therapies “Biological Markers in Retinal Vasculitis” (study number 030068) is attempting to isolate biological markers related to primary retinal vasculitis by evaluating patients with differing initial causes of the disease Additional information on either of these studies can be found at the National Eye Institute (NEI), Patient Recruitment and Public Liaison Office, 9000 Rockville Pike, Bethesda, Maryland, 20892, (800) 411-1222, TTY (866) 411-1010 Prognosis For most patients, the prognosis of Behỗet disease is good Individuals typically experience periods of active symptoms followed by periods of remission in which there are no symptoms The length of these intervals varies, with ulcerous outbreaks lasting a few weeks and other symptoms occurring for longer durations With proper treatments and medication, patients can continue to lead active lifestyles in most cases Development of vascular or neurological complications often indicates a poorer prognosis Blindness due to ocular inflammation is also prevalent in patients with BD Special concerns In cases in which a patient becomes visually impaired, major lifestyle changes take place The patient will have to learn adaptive behaviors and new forms of communication Leader dog assistance or additional caregiver support are also considerations Resources BOOKS Lee, Sungnack Behỗets Disease: A Guide to Its Clinical Understanding New York: Springer Verlag, 2001 Zeis, Joanne Essential Guide to Behỗets Disease Uxbridge, MA: Central Vision Press, 2003 PERIODICALS Okada, A A Drug Therapy in Behỗets Disease. Ocular Immunology and Inflammation (June 2001): 8591 WEBSITES Lee, Sungnack Behỗet Disease. EMedicine February 18, 2004 (May 17, 2004) 144 “Types of Vasculitis: Behỗets Disease. The Johns Hopkins Vasculitis Center Website The Johns Hopkins University 2002 (May 17, 2004) ORGANIZATIONS American Behỗets Disease Association P.O Box 19952, Amarillo, TX 79114 (800) 724-2387 jbadillo@behcets.com Behỗets Organisation Worldwide P.O Box 27, Watchet, Somerset TA23 0YJ, United Kingdom information@ behcetsuk.org National Arthritis and Musculoskeletal and Skin Diseases Information Clearinghouse 1AMS Circle, Bethesda, MD 20892 (301) 495-4484 or (877) 226-4267; Fax: (301) 718-6366 niamsinfo@mail.nih.gov Stacey L Chamberlin S Bell’s palsy Definition Bell’s palsy describes the acute onset of an unexplained weakness or paralysis of the muscles on one side of the face Afflicted individuals may be unable to close the eye on the affected side of the face, and may also experience tearing, drooling, and hypersensitive hearing on the same side The onset can be quite sudden, sometimes occurring overnight The weakness and paralysis resolve completely in the majority of cases Although it cannot be considered a serious condition from a health standpoint, it can cause extreme stress, embarrassment, and inconvenience for those affected Description Bell’s palsy has been described as a diagnosis of exclusion because several other disorders exhibit similar symptoms Facial palsies have been linked to conditions such as Lyme disease, ear infection, meningitis, syphilis, German measles (rubella), mumps, chicken pox (varicella), and infection with Epstein-Barr virus (e.g., infectious mononucleosis) True Bell’s palsy is an idiopathic facial palsy, meaning the root cause cannot be identified Although Bell’s palsy is not life-threatening, it can present symptoms similar to serious conditions such as stroke, ruptured aneurysm, or tumors Demographics Every year, approximately 40,000–65,000 Americans are stricken with Bell’s palsy Worldwide, there is an annual incidence of 20–30 cases per 100,000 individuals An GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Bell’s palsy Key Terms Antiviral A drug that prevents viruses from replicating and therefore spreading infection Computed tomography (CT) Cross-sectional x rays of the body are compiled to create a three-dimensional image of the body’s internal structures Electromyography A recording of the electrical activity generated in the muscle Facial nerve A cranial nerve that controls the muscles in the face Magnetic resonance imaging (MRI) This imaging technique uses a large circular magnet and radio waves to generate signals from atoms in the body These signals are used to construct images of internal structures Nerve conduction velocity A recording of how well a nerve conducts electrical impulses Steroid A drug used to reduce swelling and fluid accumulation individual can be affected at any age, but young and middle-aged adults are the most likely to be affected It is unusual to see Bell’s palsy in people less than 10 years old Bell’s palsy can affect either side of the face Gender does not seem to factor into risk, though pregnant women and individuals with diabetes, influenza, a cold, or an upper respiratory infection seem to be at a greater risk In the large majority of cases (80–85%), the facial weakness or paralysis is temporary However, individuals who experience complete paralysis seem to have a poorer recovery rate with only 60% returning to normal Approximately 4–6% of all Bell’s palsy cases result in permanent facial deformity, and another 10–15% experience permanent problems with spasms, twitching, or contracted muscles Between 2% and 7.3% of individuals who have had Bell’s palsy could experience a recurrence: on average, the first recurrence happens 9.8 years after the first episode; the second, 6.7 years later One recurrence is very infrequent, and a second is extremely rare Causes and symptoms The symptoms of Bell’s palsy arise from an inflammation of the seventh cranial nerve, otherwise called the facial nerve Each side of the face has a facial nerve that controls the muscles on that side of the face Inflammation leads to the interference with conduction of nerve signals, and that in turn results in the loss of muscle control and tone This boy’s facial paralysis was caused by a tick-borne meningopadiculitis (Photo Researchers, Inc Reproduced by permission.) Why the facial nerve becomes inflamed in Bell’s palsy is a matter of considerable debate Some evidence implicates the herpes simplex virus (HSV), which is responsible for cold sores and fever blisters HSV infection has been suggested in up to 70% of Bell’s palsy cases Most people harbor this virus, although they may not exhibit symptoms A number of other conditions have also been associated with the development of Bell’s palsy, including facial or head injuries, headache, repeated middle ear infections, high blood pressure, diabetes, sarcoidosis, tumors, influenza, and other viral infections, as well as Lyme disease The major symptom of Bell’s palsy is one-sided facial weakness or paralysis Muscle control is either inadequate or completely missing Patients frequently have difficulty shutting the affected eye and may not be able to close it at all Other symptoms can include pain in the jaw or behind the ear on the affected side, ringing in the ear, GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 145 Bell’s palsy headache, decreased sense of taste, hypersensitivity to sound on the affected side, difficulty with speech, dizziness, and problems eating and drinking Diagnosis Although Bell’s palsy is not life-threatening, it has similar symptoms to serious conditions such as stroke The fact that Bell’s palsy is a diagnosis of exclusion becomes apparent in the course of the medical examination—it is imperative to rule out other disorders Disorders that need to be excluded include demyelinating disease (e.g., multiple sclerosis), stroke, tumors, bacterial or viral infection, and bone fracture Therefore, emergency medical attention is a wise and necessary precaution During the evaluation, the affected individual is asked about recent illnesses, accidents, infections, and any other symptoms A visual exam of the ears, throat, and sinus is done, and hearing is tested The extent of the symptoms is assessed by grading the symmetry of the face at rest and during voluntary movements such as wrinkling the forehead, puckering the lips, and closing the affected eye Involuntary movements are assessed in combination with the voluntary movements Neurologic exam is done to rule out involvement of other parts of the nervous system Blood tests and sometimes a cerebrospinal fluid (CSF) analysis may be needed The results of these tests help determine the presence of a bacterial or viral infection or an inflammatory disease Electrophysiological tests such as electromyography and nerve conduction study, in which a muscle or nerve is artificially stimulated, may be used to assess the condition of facial muscles and the facial nerve Radiological tests may also be included, such as an x ray, magnetic resonance imaging (MRI), and computed tomography (CT) Once all other possibilities are exhausted, a diagnosis of Bell’s palsy is made During the next few weeks, the patient is carefully assessed If facial movement, even a small amount, has not returned within 3–4 months, the diagnosis of Bell’s palsy may need to be reevaluated Treatment team The patient’s primary care provider may be the initial contact; further consultation may be obtained from a neurologist and/or an ophthalmologist Physical therapists may help with pain issues and regaining function Treatment Many doctors prescribe an antiviral drug and/or a steroid for Bell’s palsy, but there is some controversy about whether these drugs actually help The consensus opinion seems to be that, although drugs might not be necessary, they are not dangerous, and they may help in 146 some cases If drugs are used, they need to be taken as soon as possible following the onset of symptoms The use of antiviral drugs such as acyclovir, famciclovir, or valacyclovir is recommended to destroy actively replicating herpes viruses Steroids such as prednisone are thought to be useful in reducing inflammation and swelling In the past, surgery was performed to relieve the compression on the nerve However, this treatment option is now used very infrequently because its benefits are uncertain, and it carries the risk of permanent nerve damage The need to protect the affected eye is universally promoted Since the individual may not be able to lower the affected eyelid, the eye may become dry, particularly at night Excessive dryness can damage the cornea Daytime treatment includes artificial tears and may include an eye patch or other protective measures Nighttime treatment involves a more intense effort at keeping the eye protected Eye lubricants or viscous ointments, along with taping the eye shut, are frequently recommended In cases of permanent nerve damage, cosmetic treatment options such as therapeutic injections of botulism toxin or surgery may be sought or suggested Prognosis Most individuals with Bell’s palsy begin to notice improvement in their condition within 2–3 weeks of the symptoms’ onset At least 80% of them will be fully recovered within three months Among the other 20% of afflicted individuals, symptoms may take longer to resolve or they may be permanent Individuals suffering permanent nerve damage may not regain control of the muscles on the affected side of the face These muscles may remain weak or paralyzed As the nerve recovers, muscles may experience involuntary facial twitches or spasms that accompany normal facial expressions Resources PERIODICALS Billue, Joyce S “Bell’s Palsy: An Update on Idiopathic Facial Palsy.” The Nurse Practitioner 22, no (1997): 88 Kakaiya, Ram “Bell’s Palsy: Update on Causes, Recognition, and Management.” Consultant 37, no (1997): 2217 ORGANIZATIONS Bell’s Palsy Research Foundation 9121 E Tanque Verde, Suite 105-286, Tucson, AZ 85749 (520) 749-4614 Julia Barrett Rosalyn Carson-DeWitt, MD Benign essential blepharospasm see Blepharospasm GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Benign intracranial hypertension see Pseudotumor cerebri S Benign positional vertigo Definition Benign positional vertigo (BPV) is the most common cause of dizziness due to an impairment of the balance center in the ear Description BPV was first described by Adler in 1987 Dix and Hallpike named the disorder benign paroxysmal positional vertigo The disorder can also be called canalithiasis or positional vertigo or “top shelf vertigo” (affected persons tip their heads back to look up when having an attack) The internal ear consists of sacs, ducts, and bone The internal portion of the ear can be divided into the bony labyrinth and membranous labyrinth The bony labyrinth is a cave-like area composed of three parts: the cochlea, vestibule, and semicircular canals The shell-shaped cochlea is the organ for hearing The vestibule is a small oval chamber that contains two structures, the utricle and the saccule, responsible for balance A membrane within the utricle and saccule normally contains particles called otoliths (calcium carbonate particles) The semicircular canals that occupy three planes in space contain the semicircular ducts for fluid (endolymph) flow The Canalolithiasis Theory, the most widely accepted explanation for the cause of BPV, explains the actual mechanism that causes BPV The theory is that otoliths can become displaced from the utricle and enter a portion of the semicircular ducts Changing head position can cause free otoliths to gravitate longitudinally through the canal The endolymph fluid contained in the semicircular canal will flow abnormally, causing stimulation of special sensors (hair cells) of the affected posterior semicircular canal duct This stimulation causes vertigo or dizziness Demographics In the United States, the number of new cases (incidence) is 64 cases per 100,000 populations per year The incidence is greater in patients older than 40 years, and women are affected twice more often than men Several studies indicate that an average age of onset in the mid50s Approximately 20% of all falls by the elderly, resulting in hospitalization for serious injuries, are due to vertigo (dizziness) No information is available concerning predilection to race Approximately 25–40% of patients with BPV express dizziness as their chief complaint The incidence among the elderly is estimated to be about 8% Causes and symptoms The most common cause of BPV is head trauma (21% of cases) with a secondary concussion The force of head trauma is thought to displace otolith particles in the semicircular canal Approximately 39% of cases not have a cause (idiopathic), and 29% of patients with BPV usually present with an existing ear disease Other common causes include alcoholism, central nervous system (CNS) disease (approximately 11%), major surgery, and chronic ear infections such as chronic otitis media (approximately 9% of cases) The severity of cases varies Some patients may experience nausea and vomiting even with the slightest head movement, whereas some patients may be minimally bothered by the dizziness As the name implies, symptoms of BPV are typically dependent on head position Head movement, rolling in bed, leaning forward or backward, or changing posture can cause an attack The symptoms start abruptly and disappear with 20–30 seconds Diagnosis In addition to a detailed history, the physical examination is important for detection of characteristic physical signs such as nystagmus (involuntary rhythmic oscillation of the eyes) The examination is also necessary to exclude other neurological diseases that may mimic benign positional vertigo A physician familiar with the condition may perform the Hallpike test Also, in patients with vertigo, hearing tests are generally necessary Further testing may be necessary to evaluation other conditions that can cause vertigo or dizziness Treatment team The treatment team can consist of an emergency room physician, ear, nose, and throat (ENT) specialist-surgeon, neurologist, and audiologist A primary care practitioner can initiate symptomatic management Patients typically require follow-up care and monitoring Surgical candidates require specialty care from an ENT surgeon, as well as and a surgical team in a hospital that is equipped for such an intervention Treatment There are three types of treatment given to patients with BPV: medical care, surgery, and home treatment Medical care (office treatment) consists of either the Semont maneuver (also referred to as the Liberaroty maneuver) or the Epley maneuver, named after their GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 147 Benign positional vertigo Benign focal amyotrophy see Monomelic amyotrophy Benzodiazepines studied, 70% had resolution of symptoms within two days after treatment Key Terms Sensorium The place in the brain where external expressions are localized and processed before being perceived inventors The Semont maneuver (a series of head-turning exercises) involves a rapid shift from lying on one side to lying on the opposite side The Epley maneuver involves sequentially moving the head in four different positions and waiting for 30 seconds on each turn These maneuvers are effective in approximately 80% of patients who are diagnosed with BPV, although symptoms may reoccur after initial improvement in a substantial percentage of patients If office medical treatment fails, patients can continue treatment at home with the Brandt-Daroff Exercises, which are difficult to perform, but effective in 95% of cases These exercises are time consuming and done in three sets per day for two weeks Medical treatment with medications is not recommended since they not help relieve symptoms A surgical procedure called posterior canal plugging can be utilized in patients who had no response to any other form of treatment With this procedure, there is a small risk of hearing deficit (usually less than 20%), but it is effective in most patients The posterior semicircular canal is excised, exposing the membranous labyrinth with floating otoliths The canal is patched off with tissue so otolith particles cannot move into the canal to stimulate the hair cells within this area The canal is sealed and the incision sutured Typically, the patient will stay in the hospital overnight and return one week later for suture removal Prognosis The overall prognosis for patients who suffer from BPV is good Spontaneous remission can occur within six weeks, but some cases never remit Once treated, the recurrence rate is between 5% and 15% Resources BOOKS Goldman, Lee, et al Cecil’s Textbook of Medicine, 21st ed Philadelphia: WB Saunders Company, 2000 PERIODICALS Chang, Andrew K “Benign Positional Vertigo.” eMedicine Series (April 2002) Haynes, D S “Treatment of Benign Positional Vertigo Using the Semont Maneuver: Efficacy in Patients Presenting without Nystagmus.” Laryngoscope 112:5 (May 2002) Li, John “Benign Positional Vertigo.” eMedicine Series (December 2001) WEBSITES “Benign Positional Vertigo.” (May 17, 2004.) “Benign Positional Vertigo.” (May 17, 2004.) ORGANIZATIONS American Hearing Research Association Foundation South Michigan Avenue, Suite 814, Chicago, IL 60603-4539 (312) 726-9670; Fax: (312) 726-9695 Laith Farid Gulli, MD Robert Ramirez, DO Nicole Mallory, MS,PA-C Recovery and rehabilitation Recovery and rehabilitation is favorable Most patients recover well with head-tilting exercises Patients who have recurrence of symptoms will undergo further exercises or surgical correction, which is successful for resolution of symptoms in more than 90% of surgical candidates Clinical trials A large study is currently active concerning the treatment of BPV in family practice at McMaster University Department of Family Medicine in Hamilton, Ontario, Canada Contact is Shawn Ling at (905) 521-2100 ext 75451; fax: (905) 521-5010; e-mail: lingfpu@yahoo.ca Clinical trials as of 2001 reported good results using the Epley canalith repositioning maneuver In 86 patients 148 S Benzodiazepines Definition Benzodiazepines are medicines that help relieve nervousness, tension, and other symptoms by slowing the central nervous system Purpose Benzodiazepines are a type of antianxiety drugs While anxiety is a normal response to stressful situations, some people have unusually high levels of anxiety that can interfere with everyday life For these people, benzodiazepines can help bring their feelings under control The GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Description The family of antianxiety drugs known as benzodiazepines includes alprazolam (Xanax), chlordiazepoxide (Librium), diazepam (Valium), and lorazepam (Ativan) These medicines take effect fairly quickly, starting to work within an hour after they are taken Benzodiazepines are available only with a physician’s prescription and are available in tablet, capsule, liquid, or injectable forms Recommended dosage The recommended dosage depends on the type of benzodiazepine, its strength, and the condition for which it is being taken Doses may be different for different people Check with the physician who prescribed the drug or the pharmacist who filled the prescription for the correct dosage Always take benzodiazepines exactly as directed Never take larger or more frequent doses, and not take the drug for longer than directed If the medicine does not seem to be working, check with the physician who prescribed it Do not increase the dose or stop taking the medicine unless the physician says to so Stopping the drug suddenly may cause withdrawal symptoms, especially if it has been taken in large doses or over a long period People who are taking the medicine for seizure disorders may have seizures if they stop taking it suddenly If it is necessary to stop taking the medicine, check with a physician for directions on how to stop The physician may recommend tapering down gradually to reduce the chance of withdrawal symptoms or other problems Precautions Seeing a physician regularly while taking benzodiazepines is important, especially during the first few months of treatment The physician will check to make sure the medicine is working as it should and will note unwanted side effects People who take benzodiazepines to relieve nervousness, tension, or symptoms of panic disorder should check with their physicians every two to three months to make sure they still need to keep taking the medicine Patients who are taking benzodiazepines for sleep problems should check with their physicians if they are not sleeping better within 7-10 days Sleep problems that last longer than this may be a sign of another medical problem People who take this medicine to help them sleep may have trouble sleeping when they stop taking the medicine This effect should last only a few nights Some people, especially older people, feel drowsy, dizzy, lightheaded, or less alert when using benzodiazepines The drugs may also cause clumsiness or unsteadiness When the medicine is taken at bedtime, these effects may even occur the next morning Anyone who takes these drugs should not drive, use machines, or anything else that might be dangerous until they have found out how the drugs affect them Benzodiazepines may also cause behavior changes in some people, similar to those seen in people who act differently when they drink alcohol More extreme changes, such as confusion, agitation, and hallucinations, also are possible Anyone who starts having strange or unusual thoughts or behavior while taking this medicine should get in touch with his or her physician Because benzodiazepines work on the central nervous system, they may add to the effects of alcohol and other drugs that slow down the central nervous system, such as antihistamines, cold medicine, allergy medicine, sleep aids, medicine for seizures, tranquilizers, some pain relievers, and muscle relaxants They may also add to the effects of anesthetics, including those used for dental procedures These effects may last several days after treatment with benzodiazepines ends The combined effects of benzodiazepines and alcohol or other CNS depressants (drugs that slow the central nervous system) can be very dangerous, leading to unconsciousness or, rarely, even death Anyone taking benzodiazepines should not drink alcohol and should check with his or her physician before using any CNS depressants Taking an overdose of benzodiazepines can also cause unconsciousness and possibly death Anyone who shows signs of an overdose or of the effects of combining benzodiazepines with alcohol or other drugs should get immediate emergency help Warning signs include slurred speech or confusion, severe drowsiness, staggering, and profound weakness Some benzodiazepines may change the results of certain medical tests Before having medical tests, anyone taking this medicine should alert the health care professional in charge Children are generally more sensitive than adults to the effects of benzodiazepines This sensitivity may increase the chance of side effects GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 149 Benzodiazepines medicine can also relieve troubling symptoms of anxiety, such as pounding heartbeat, breathing problems, irritability, nausea, and faintness Physicians may sometimes prescribe these drugs for other conditions, such as muscle spasms, epilepsy and other seizure disorders, phobias, panic disorder, withdrawal from alcohol, and sleeping problems However, this medicine should not be used every day for sleep problems that last more than a few days If used this way, the drug loses its effectiveness within a few weeks Benzodiazepines should not be used to relieve the nervousness and tension of normal everyday life Benzodiazepines Key Terms Anxiety Worry or tension in response to real or imagined stress, danger, or dreaded situations Physical reactions, such as fast pulse, sweating, trembling, fatigue, and weakness may accompany anxiety Asthma A disease in which the air passages of the lungs become inflamed and narrowed Bronchitis Inflammation of the air passages of the lungs Central nervous system The brain, spinal cord, and the nerves throughout the body Chronic A word used to describe a long-lasting condition Chronic conditions often develop gradually and involve slow changes Emphysema An irreversible lung disease in which breathing becomes increasingly difficult Epilepsy A brain disorder with symptoms that include seizures Myasthenia gravis A chronic disease with symptoms that include muscle weakness and sometimes paralysis Panic disorder A disorder in which people have sudden and intense attacks of anxiety in certain situations Symptoms such as shortness of breath, sweating, dizziness, chest pain, and extreme fear often accompany the attacks Phobia An intense, abnormal, or illogical fear of something specific, such as heights or open spaces Porphyria A disorder in which porphyrins build up in the blood and urine Porphyrin A type of pigment found in living things Seizure A sudden attack, spasm, or convulsion Sleep apnea A condition in which a person temporarily stops breathing during sleep Glaucoma A condition in which pressure in the eye is abnormally high If not treated, glaucoma may lead to blindness Withdrawal symptoms A group of physical or mental symptoms that may occur when a person suddenly stops using a drug to which he or she has become dependent Older people are more sensitive than younger adults to the effects of this medicine and may be at greater risk for side effects Older people who take these drugs to help them sleep may be drowsy during the day Older people also increase their risk of falling and injuring themselves when they take these drugs Women who are pregnant or who may become pregnant should not use benzodiazepines unless their anxiety is so severe that it threatens their pregnancy Any woman who must take this medicine while pregnant should be sure to thoroughly discuss its risks and benefits with her physician Special conditions People with certain medical conditions or who are taking certain other medicines can have problems if they take benzodiazepines Before taking these drugs, be sure to let the physician know about any of these conditions: ALLERGIES Anyone who has had unusual reactions to benzodiazepines or other mood-altering drugs in the past should let his or her physician know before taking the drugs again The physician should also be told about any allergies to foods, dyes, preservatives, or other substances PREGNANCY Some benzodiazepines increase the likelihood of birth defects Using these medicines during pregnancy may also cause the baby to become dependent on them and to have withdrawal symptoms after birth When taken late in pregnancy or around the time of labor and delivery, these drugs can cause other problems in the newborn baby, such as weakness, breathing problems, slow heartbeat, and body temperature problems 150 BREAST-FEEDING Benzodiazepines may pass into breast milk and cause problems in babies whose mothers take the medicine These problems include drowsiness, breathing problems, and slow heartbeat Women who are breast-feeding their babies should not use this medicine without checking with their physicians OTHER MEDICAL CONDITIONS Before using benzodiazepines, people with any of these medical problems should make sure their physicians are aware of their conditions: • current or past drug or alcohol abuse • depression • severe mental illness • epilepsy or other seizure disorders • swallowing disorders • chronic lung disease such as emphysema, asthma, or chronic bronchitis GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS • irritability • liver disease • nervousness • brain disease • sleep problems • glaucoma Other rare side effects may occur Anyone who has unusual symptoms during or after treatment with benzodiazepines should get in touch with his or her physician • hyperactivity • myasthenia gravis Beriberi • kidney disease • porphyria • sleep apnea USE OF CERTAIN MEDICINES Taking benzodiazepines with certain other drugs may affect the way the drugs work or may increase the chance of side effects Side effects The most common side effects are dizziness, lightheadedness, drowsiness, clumsiness, unsteadiness, and slurred speech These problems usually go away as the body adjusts to the drug and not require medical treatment unless they persist or they interfere with normal activities Interactions Benzodiazepines may interact with a variety of other medicines When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater Anyone who takes benzodiazepines should let the physician know all other medicines he or she is taking Among the drugs that may interact with benzodiazepines are: • central nervous system (CNS) depressants such as medicine for allergies, colds, hay fever, and asthma • sedatives • tranquilizers More serious side effects are not common, but may occur If any of the following side effects occur, check with the physician who prescribed the medicine as soon as possible: • prescription pain medicine • behavior changes • sleep aids • memory problems • barbiturates • difficulty concentrating • anesthetics • confusion Medicines other than those listed above may interact with benzodiazepines Be sure to check with a physician or pharmacist before combining benzodiazepines with any other prescription or nonprescription (over-the-counter) medicine • depression • seizures (convulsions) • hallucinations • muscle relaxants • medicine for seizures • sleep problems • increased nervousness, excitability, or irritability Resources • involuntary movements of the body, including the eyes OTHER • low blood pressure “Medications.” National Institute of Mental Health Page 1995 • unusual weakness or tiredness Nancy Ross-Flanigan • skin rash or itching • unusual bleeding or bruising • yellow skin or eyes S Beriberi • sore throat • sores in the mouth or throat • fever and chills Patients who take benzodiazepines for a long time or at high doses may notice side effects for several weeks after they stop taking the drug They should check with their physicians if these or other troublesome symptoms occur: Definition Beriberi is a condition caused by severe prolonged deficiency of vitamin B1 (also known as thiamine) Beriberi refers to a constellation of heart, gastrointestinal, and nervous system problems from thiamine deficiency GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 151 Beriberi Description • enlarged heart Thiamine is found in a variety of foods, particularly whole grains, legumes, and pork Thiamine serves as a coenzyme in the chemical pathway responsible for the metabolism of carbohydrates Thiamine deficiency interferes with the metabolism of glucose and the production of energy Four major types of beriberi exist: wet beriberi, which affects primarily the cardiovascular system; dry beriberi, which affects primarily the nervous system; shoshin, which is a rapidly evolving and frequently fatal form of cardiovascular beriberi; and infantile beriberi, which tends to strike babies between the ages of one and four months who are breastfed by mothers who are severely thiamine deficient • enlarged, tender liver • shortness of breath • congestion in the lungs Symptoms of shoshin beriberi are the same as those of wet beriberi, but the onset is sudden, the progression is rapid, and the risk of death is very high Symptoms of infantile beriberi include: • restlessness • difficulty sleeping • diarrhea • swollen arms and legs • muscle wasting in arms and legs Demographics • silent cry Because so many foods in the United States and other western countries are vitamin enriched, beriberi is extremely rare In developed countries, beriberi is primarily a complication of malnutrition secondary to alcoholism or gastrointestinal disorders Because alcoholism affects more males than females, rates of beriberi in developed countries are higher among males The syndrome of symptoms caused by thiamine deficiency in alcoholism is called Wernicke-Korsakoff syndrome In developing countries, where diets are more limited, beriberi is endemic In some areas of Asia, people subsist on polished rice, in which the outer, more nutritious husk is removed The rates of beriberi in these areas are quite high In certain parts of Indonesia, the prevalence of beriberi among low-income families is as high as 66% The majority of patients with beriberi are infants (ages 1–4 months) and adults Causes and symptoms Symptoms of beriberi are caused by abnormal metabolism of carbohydrates throughout the body, resulting in a decreased production of energy, and particular injury to the heart muscle and the nervous system Symptoms of dry beriberi include: • numbness, tingling, burning pain in extremities • pain and cramping in the leg muscles • difficulty with speech • problems walking • disturbed sense of balance Symptoms of wet beriberi include: • fast heart rate • swollen feet and legs 152 • heart failure Symptoms may coexist with other disorders due to thiamine deficiency such as Wernicke-Korsakoff encephalopathy In such cases, confusion, memory loss, difficulty with eye movements, and even coma may occur Diagnosis The first step to diagnosis includes taking a careful history to uncover a possible underlying cause for thiamine deficiency Physical examination will demonstrate some of the expected signs of beriberi, such as swelling, decreased reflexes, decreased sensation, problems with walking or balance, etc Laboratory testing to demonstrate thiamine deficiency includes measurements of thiamine in the blood; tests of the activity of thiamine in whole blood or red blood cells (called transketolase activity), both before and after the administration of thiamine; measurements of the chemicals lactate and pyruvate in the blood (these will be increased in beriberi); and measurements of the amount of thiamine passed into the urine (this will be decreased in beriberi) In some cases, the diagnosis of beriberi is made only after thiamine supplementation results in a resolution of the patient’s symptoms Treatment team Depending on how a patient enters the health care system, an emergency room physician, internal medicine physician, family practitioner, neurologist, gastroenterologist, or cardiologist may treat a patient for beriberi A nutritionist should be consulted to develop a nutritional plan If alcoholism is an underlying problem, the patient GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Brown-Séquard syndrome Prognosis Symptoms of malignant brain and spinal cord tumors are usually progressive over time Symptoms become more pronounced and troublesome as tumors invade or otherwise obstruct healthy tissue Benign tumors can also cause severe dysfunction by placing pressure on surrounding vital structures, but with treatment, they have a more favorable prognosis The slowest growing and least serious of these tumor types, grade II astrocytomas (a “low grade” tumor) can still infiltrate surrounding tissue and thus hold a potential for malignancy Grade III anaplastic astrocytomas are more malignant than type II tumors This increase in malignancy translates into lower long-term survival rates Many persons with grade III anaplastic astrocytomas die within two to three years, while may people with the grade II astrocytoma show long-term survival beyond five years Patients with the most severe form of astrocytoma (glioblastoma multiforme, or GBH) usually show survival times of less than two years Patients with oligodendrogliomas and oligoastrocytomas have generally better prognoses than the diffuse astrocytomas Brainstem gliomas (a form of pediatric diffuse, fibrillary astrocytoma) have a tendency toward malignancy, and survival beyond two years is unusual Because PXA tumors are usually slow growing and superficial, they are therefore more likely to be successfully treated by surgical removal Primary tumors of the spinal cord are often benign, and surgical removal results in a favorable prognosis With metastatic spinal tumors, prognosis depends on the type of primary cancer Resources ORGANIZATIONS American Brain Tumor Association (ABTA) 2720 River Road, Des Plaines, IL 60018-4110 (847) 827-9910; Fax: (847) 827-9918 info@abta.org National Cancer Institute (NCI), National Institutes of Health Bldg 31, Rm 10A31, Bethesda, MD 20892-2580 (301) 435-3848 or (800) 4CANCER (422-6237); Fax: (847) 827-9918 cancermail@icicc.nci.nih.gov Paul Arthur S Brown-Séquard syndrome Definition Brown-Séquard syndrome (BSS), also known as hemisection of the spinal cord or partial spinal sensory syndrome, is a rare condition caused by an incomplete lesion of the spinal cord This damage, most often from physical trauma, results in a contralateral (opposite side of the body) loss of sensation and temperature and ipsilateral (same side of the body) paralysis or extreme weakness BOOKS Goetz C G., et al Textbook of Clinical Neurology Philadelphia: W.B Saunders Company, 1999 Guyton & Hall Textbook of Medical Physiology, 10th ed Philadelphia: W.B Saunders Company, 2000 Roloff, Tricia Ann Navigating through a Strange Land: A Book for Brain Tumor Patients and Their Families Minneapolis, MN: Fairview Press, 2001 Shiminski-Maher, Tania Childhood Brain & Spinal Cord Tumors: A Guide for Families, Friends & Caregivers Sebastopol, CA: O’Reilly & Associates, 2001 Stark-Vance, Virginia 100 Q & A about Brain Tumors Sudbury, MA: Jones & Bartlett, 2003 Description OTHER “Brain and Spinal Cord Tumors—Hope through Research.” National Institute of Neurological Disorders and Stroke May 2, 2004 (May 22, 2004) “Facts About Brain Tumors.” National Brain Tumor Foundation May 2, 2004 (May 22, 2004) 180 Francavilla, Thomas L “Intramedullary Spinal Cord Tumors.” eMedicine May 2, 2004 (May 22, 2004) “Living with a Brain Tumor: A Guide for Brain Tumor Patients.” American Brain Tumor Association May 2, 2004 (May 22, 2004) “NINDS Brain and Spinal Tumors Information Page.” National Institute of Neurological Disorders and Stroke May 4, 2004 (May 22, 2004) “What You Need To Know about Brain Tumors.” National Cancer Institute May 2, 2004 (May 22, 2004) In 1849, French physiologist Charles Edouard Brown-Séquard published a document discussing the condition that now bears his name Using information gathered through animal experimentation and human autopsies, he identified and described the hallmark signs of BSS: paralysis affecting only one side of the body (ipsilateral paralysis) and loss of sensation on the opposite side of the body Injury or damage to one side of the spinal cord, typically in the cervical (neck) region, results in BSS The GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Demographics Information on the prevalence of Brown-Séquard syndrome is collected from 16 spinal cord injury centers in the United States According to The University of Alabama’s National Spinal Cord Injury Statistical Center (NSCISC), which compiles the data, approximately 11,000 spinal cord injuries (SCIs) occur each year (as of 2003) Although specific incidence is unknown, BSS is estimated to occur in 200–400 of these injuries Key Terms Corticosteroids A group of anti-inflammatory drugs similar to the natural corticosteroid hormones produced by the adrenal glands Lesion A change in tissue due to injury or disease Paralysis The inability to use a muscle because of injury to or disease of the nerves leading to the muscle The average age of a patient sustaining a spinal cord injury is 32 years, with injuries most commonly occurring in individuals between 16 and 30 years Men account for more than 80% of reported SCIs and location of the SCI These include magnetic resonance imaging (MRI), computed tomography (CT) scans, or x rays Additional testing may be required for secondary conditions or symptoms Within the United States, approximately 70% of individuals with BSS are white, nearly 20% are African American, and the remaining 10% comprise other origins, according to NSCISC reports Little data is known regarding SCIs in countries outside the United States Several neurological disorders have symptoms similar to BSS, making differential diagnosis very important, especially in those cases related to nontraumatic conditions The incomplete lesion of the spinal cord in conjunction with the unique presentation of ipsilateral sensory loss and paralysis are key for identifying BSS Causes and symptoms In most cases, Brown-Séquard syndrome is caused by severe physical trauma such as a puncture wound or gunshot wound, which partially severs or damages the spinal cord Nontraumatic conditions that compress the spinal cord may also cause BSS Examples include tumors, multiple sclerosis, epidural hematoma (swelling in the area between the brain and skull), meningitis, myelitis (spinal cord inflammation), and tuberculosis Physical trauma usually causes a more rapid onset of symptoms than nontraumatic conditions The two primary symptoms of BSS are loss of sensation and paralysis The side of the body that sustained injury typically loses touch and vibration senses The opposite side of the body tends to lose its sense of pain and temperature In both cases, these symptoms occur below the site of the SCI Paralysis or muscle weakness occurs on the same side of the body as the injury Loss of bladder and bowel control may result, but the majority of patients will regain control Horner syndrome, a condition resulting from damage to the sympathetic facial nerves, has also been known to develop Diagnosis Brown-Séquard syndrome is diagnosed based on the patient’s medical history and a physical examination Imaging studies may be performed to isolate the extent Treatment team The team of specialists needed to treat a patient with BSS will vary Primary members include: • a neurologist to evaluate brain and nerve function • an orthopedic specialist to monitor the spine and assist with walking therapy • a physical therapist to help regain muscle strength and walking ability • an occupational therapist to facilitate adaptation of new physical limitations Treatment In cases of physical trauma, treatment begins at the accident site with proper immobilization and emergency medical care to prevent further spinal cord damage Surgery may be required in these or nontraumatic cases to eliminate the cause, whether a bullet or a fluid-filled cyst Treatment of symptoms is the typical focus for this condition Several studies have shown increased success with early administration of high-dose steroids such as corticosteroids, but this is not yet a standard practice Other medications are prescribed as needed for secondary symptoms Physical therapy should begin immediately in order to maintain muscle strength and agility since most patients GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 181 Brown-Séquard syndrome severity of the condition depends on the amount of damage to the spinal cord and associated neurons The onset of symptoms may also vary depending on the cause Brown-Séquard syndrome with BSS will regain mobility Specialized devices, including wheelchairs or braces, may be necessary during this transition Recovery and rehabilitation Resources The recovery time for each patient depends on the extent of nerve damage and underlying cause of the syndrome The NSCISC reports that individuals with SCIs spend an average of 16 days in the hospital and 44 days in rehabilitation Rehabilitation may be required outside the hospital for several months or years Extensive physical therapy should take place immediately Initial therapy focuses on respiratory exercises, upright positioning, and range of motion in affected muscles Progressive therapy gradually helps the patient with the strength and control necessary to be mobile or begin walking again Occupational therapy is also important for helping patients return to their daily activities This therapist provides methods for modifying everyday tasks, evaluates progress, and facilitates the necessary changes to restore independence when possible Clinical trials BOOKS The Official Patient’s Sourcebook on Brown-Séquard Syndrome: A Revised and Updated Directory for the Internet Age San Diego: Icon Health Publications, 2002 PERIODICALS Bateman, D E., and I Pople “Brown-Séquard at Disney World.” The Lancet 352, no 9144 (December 12, 1998): 1902 Lim, E., Y S Wong, Y L Lo, et al “Traumatic Atypical Brown-Séquard Syndrome: Case Report and Literature Review.” Clinical Neurology and Neurosurgy 105 (2003): 143–45 Pollard, Matthew E., and David F Apple “Factors Associated with Improved Neurologic Outcomes in Patients with Incomplete Tetraplegia.” Spine 28, no (January 1, 2003): 33–39 Tattersall, Robert, and Benjamine Turner “Brown-Séquard and His Syndrome.” The Lancet 356, no 9223 (July 1, 2000): 61 WEBSITES The National Institute of Child Health and Human Development is currently conducting a clinical trial to evaluate the effectiveness of walking on a treadmill by individuals with incomplete SCIs As of early 2004, this five-year study was in Phase II and III clinical trials and still recruiting patients The proposed end date for the study is January 2005 For additional information contact: Andrea L Behrman, PhD (Principal Investigator), University of Florida, “Retraining Walking after Spinal Cord Injury” (Study ID: K01HD01348); Telephone: (352) 2736117; E-mail: abehrman@hp.ufl.edu Prognosis Patients with Brown-Séquard syndrome usually have a good prognosis The extent to which a patient recovers depends on the cause of injury and secondary conditions or complications According to the National Organization for Rare Disorders, more than 90% of affected individuals successfully regain the ability to walk Additional studies have found that the majority of a patient’s motor skills return within the first two months after injury The recovery period is usually two years, but will vary by patient Beeson, Michael S, and Scott Wilber “Brown-Séquard Syndrome.” eMedicine July 30, 2003 (May 20, 2004) “Retraining Walking after Spinal Cord Injury.” ClinicalTrials.gov March 19, 2004 (May 20, 2004) Vandenakker, Carol “Brown-Séquard Syndrome.” eMedicine July 29, 2002 (May 20, 2004) ORGANIZATIONS Christopher Reeve Paralysis Foundation 500 Morris Avenue, Springfield, NJ 07081 (800) 225-0292 info@paralysis.org National Organization for Rare Disorders 55 Kenosia Avenue, P.O Box 1968, Danbury, CT 06813 (203) 744-0100 or (800) 999-6673; Fax: (203) 798-2291 orphan@rare diseases.org National Spinal Cord Injury Association 6701 Democracy Blvd #300-9, Bethesda, MD 20817 (301) 214-4006 or (800) 962-9629; Fax: (301) 881-9817 info@spinalcord.org Stacey L Chamberlin Bruit see Hearing disorders Special concerns Not all patients with BSS make a full recovery In these instances, long-term care options need to be considered By working with the treatment team, individuals can 182 determine their level of activity and recognize areas where adaptation may be required Some patients and their caregivers could benefit from psychological therapy to discuss the variety of changes that occur after traumatic injury Bulbospinal muscular atrophy see Kennedy’s disease GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS C S Canavan disease Definition Canavan disease, which results when the body produces less than normal amounts of a protein called aspartoacylase, is a fatal inherited disorder characterized by progressive damage to the brain and nervous system Description Canavan disease is named after Dr Myrtelle Canavan who described a patient with the symptoms of Canavan disease but mistakenly diagnosed this patient with Schilder’s disease It was not until 1949, that Canavan disease was recognized as a unique genetic disease by Van Bogaert and Betrand The credit went to Dr Canavan, however, whose initial description of the disease dominated the medical literature Canavan disease, which is also called aspartoacylase deficiency, spongy degeneration of the brain, and infantile spongy degeneration, results from a deficiency of the enzyme aspartoacylase This deficiency ultimately results in progressive damage to the brain and nervous system and causes mental retardation, seizures, tremors, muscle weakness, blindness and an increase in head size Although most people with Canavan disease die in their teens, some die in childhood and some live into their twenties and thirties Canavan disease is sometimes called spongy degeneration of the brain since it is characterized by a sponginess or swelling of the brain cells and a destruction of the white matter of the brain Canavan disease is an autosomal recessive genetic condition that is found in all ethnic groups, but is most common in people of Ashkenazi (Eastern European) Jewish descent and people of Saudi Arabian descent Demographics Although Canavan disease is found in people of all ethnicities, it is most common in Ashkenazi Jewish individuals Approximately one in 40 Ashkenazi Jewish individuals are carriers for Canavan disease and approximately one in 6,400 Ashkenazi Jewish people are born with Canavan disease People of Saudi Arabian descent also have a relatively high risk of Canavan disease Causes and symptoms Canavan disease is an autosomal recessive genetic disease A person with Canavan disease has changes (mutations) in both of the genes responsible for producing the enzyme aspartoacylase and has inherited one changed gene from his or her mother and one changed gene from his or her father Reduced production of aspartoacylase results in lower than normal amounts of this enzyme in the brain and nervous system Aspartoacylase is responsible for breaking down a substance called N-acetylaspartic acid (NAA) When the body produces decreased levels of aspartoacylase, a build-up of NAA results This results in the destruction of the white matter of the brain and nervous system and causes the symptoms of Canavan disease Parents who have a child with Canavan disease are called carriers, since they each possess one changed ASPA gene and one unchanged ASPA gene Carriers usually not have any symptoms since they have one unchanged gene that can produce enough aspartoacylase to prevent the build-up of NAA Each child born to parents who are both carriers for Canavan disease, has a 25% chance of having Canavan disease, a 50% chance of being a carrier and a 25% chance of being neither a carrier nor affected with Canavan disease Most infants with Canavan disease appear normal for the first month of life The onset of symptoms, such as a lack of head control and poor muscle tone, usually begins by two to three months of age, although some may have an onset of the disease in later childhood Children with Canavan disease usually experience sleep disturbances, irritability, and swallowing and feeding difficulties after the first or second year of life In many cases, irritability resolves by the third year As the child with Canavan disease GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 183 Canavan disease grows older there is a deterioration of mental and physical functioning The speed at which this deterioration occurs will vary for each affected person Children with Canavan disease are mentally retarded and most will never be able to sit, stand, walk or talk, although they may learn to laugh and smile and reach for objects People with Canavan disease have increasing difficulties in controlling their muscles Initially they have poor muscle tone but eventually their muscles become stiff and difficult to move and may exhibit spasms Canavan disease can cause vision problems and some people with Canavan disease may eventually become blind People with Canavan disease typically have disproportionately large heads and may experience seizures Diagnosis Diagnostic testing Canavan disease should be suspected in a person with a large head who has poor muscle control, a lack of head control and a destruction of the white matter of the brain, which can be detected through a computed tomography (CT) scan or magnetic resonance imaging (MRI) A diagnosis of Canavan disease can usually be confirmed by measuring the amount of NAA in a urine sample since a person with Canavan disease typically has greater than five to ten times the normal amount of NAA in their urine Canavan disease can be less accurately diagnosed by measuring the amount of aspartocylase enzyme present in a sample of skin cells Once a biochemical diagnosis of Canavan disease is made, DNA testing may be recommended Detection of an ASPA gene alteration in a person with Canavan disease can confirm an uncertain diagnosis and help facilitate prenatal diagnosis and carrier testing of relatives Although there are a number of different ASPA gene changes responsible for Canavan disease, most clinical laboratories typically test for only two to three common gene changes Two of the ASPA gene changes are common in Ashkenazi Jews with Canavan disease and the other ASPA gene change is common in those of other ethnic backgrounds Testing for other types of changes in the ASPA gene is only done on a research basis be less accurate Carrier testing for the three common ASPA gene mutations identifies approximately 97–99% of Ashkenazi Jewish carriers and 40–55% of carriers from other ethnic backgrounds Carrier testing of individuals without a family history of Canavan disease is only recommended for people of Ashkenazi Jewish background since they have a higher risk of being carriers As of 1998, both the American College of Obstetricians and Gynecologists and the American College of Medical Genetics recommend that DNA testing for Canavan disease be offered to all Ashkenazi Jewish couples who are planning children or who are currently pregnant If only one member of the couple is of Ashkenazi Jewish background than testing of the Jewish partner should be performed first If the Jewish partner is a carrier, than testing of the non-Jewish partner is recommended Prenatal testing Prenatal testing through chorionic villus sampling (CVS) and amniocentesis is available to parents who are both carriers for Canavan disease If both parents possess an ASPA gene change, which is identified through DNA testing, then DNA testing of their baby can be performed Some parents are known to be carriers for Canavan disease since they already have a child with Canavan disease, yet they not possess ASPA gene changes that are detectable through DNA testing Prenatal diagnosis can be performed in these cases by measuring the amount of NAA in the amniotic fluid obtained from an amniocentesis This type of prenatal testing is less accurate than DNA testing and can lead to misdiagnoses Treatment team A child with Canavan disease will require treatment from a pediatric neurologist, pediatric ophthalmologist, and a pediatric surgeon for the installation of certain kinds of feeding tubes Physical and occupational therapists can and educational specialists can provide supportive treatment Treatment Carrier testing DNA testing is the only means of identifying carriers of Canavan disease If possible, DNA testing should be first performed on the affected family member If a change in the ASPA gene is detected, then carrier testing can be performed in relatives such as siblings, with an accuracy of greater than 99% If the affected relative does not possess a detectable ASPA gene change, then carrier testing will be inaccurate and should not be performed If DNA testing of the affected relative cannot be performed, carrier testing of family members can still be performed but will 184 There is no cure for Canavan disease and treatment largely involves the management of symptoms Seizures and irritability can often be controlled through medication Children with loss of head control will often benefit from the use of modified seats that can provide full head support When feeding and swallowing becomes difficult, liquid diets and/or feeding tubes become necessary Feeding tubes are either inserted through the nose (nasogastric tube) or through a permanent incision in the stomach (gastrostomy) Patients with a later onset and slower progression of the disease may benefit from special education GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Amniocentesis A procedure performed at 16-18 weeks of pregnancy in which a needle is inserted through a woman’s abdomen into her uterus to draw out a small sample of the amniotic fluid from around the baby Either the fluid itself or cells from the fluid can be used for a variety of tests to obtain information about genetic disorders and other medical conditions in the fetus Amniotic fluid The fluid which surrounds a developing baby during pregnancy Amniotic sac Contains the fetus which is surrounded by amniotic fluid Biochemical testing Measuring the amount or activity of a particular enzyme or protein in a sample of blood or urine or other tissue from the body Carrier A person who possesses a gene for an abnormal trait without showing signs of the disorder The person may pass the abnormal gene on to offspring Chorionic villus sampling (CVS) A procedure used for prenatal diagnosis at 10-12 weeks gestation Under ultrasound guidance a needle is inserted either through the mother’s vagina or abdominal wall and a sample of cells is collected from around the early embryo These cells are then tested for chromosome abnormalities or other genetic diseases Chromosome A microscopic thread-like structure found within each cell of the body and consists of a complex of proteins and DNA Humans have 46 chromosomes arranged into 23 pairs Changes in programs and physical therapy Research trials of gene therapy are ongoing and involve the transfer of an unchanged ASPA gene into the brain cells of a patient The goal of gene therapy is to restore normal amounts of aspartoacylase in the brain and nervous system and prevent the build-up of NAA and the symptoms of Canavan disease The initial results of these early clinical trials have been somewhat promising but it will take time for gene therapy to become a viable treatment for Canavan disease Prognosis The life span and progression of Canavan disease is variable and may be partially dependent on the type of medical care provided and other genetic risk factors Most people with Canavan disease live into their teens, although some die in infancy or survive into their 20’s and 30’s either the total number of chromosomes or their shape and size (structure) may lead to physical or mental abnormalities Deoxyribonucleic acid (DNA) The genetic material in cells that holds the inherited instructions for growth, development, and cellular functioning DNA testing Analysis of DNA (the genetic component of cells) in order to determine changes in genes that may indicate a specific disorder Enzyme A protein that catalyzes a biochemical reaction or change without changing its own structure or function Gene A building block of inheritance, which contains the instructions for the production of a particular protein, and is made up of a molecular sequence found on a section of DNA Each gene is found on a precise location on a chromosome Poor muscle tone Muscles that are weak and floppy Prenatal testing Testing for a disease such as a genetic condition in an unborn baby Protein Important building blocks of the body, composed of amino acids, involved in the formation of body structures and controlling the basic functions of the human body White matter A substance found in the brain and nervous system that protects nerves and allows messages to be sent to and from the brain to the various parts of the body There can be a high degree of variability even within families; some families report having one child die in infancy and another die in adulthood Although different ASPA gene changes are associated with the production of different amounts of enzyme, the severity of the disease does not appear to be related to the type of ASPA gene change It is, therefore, impossible to predict the life span of a particular individual with Canavan disease Resources BOOKS Scriver, C R., et al., eds The Metabolic and Molecular Basis of Inherited Disease New York: The McGraw Hill Companies, 1995 PERIODICALS ACOG committee opinion “Screening for Canavan disease.” Number 212, November 1998 Committee on Genetics GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 185 Canavan disease Key Terms Carbamazepine American College of Obstetricians and Gynecologists International Journal of Gynaecology and Obstetrics 65, no (April 1999): 91–92 Definition Besley, G T N., et al “Prenatal Diagnosis of Canavan Disease–Problems and Dilemmas.” Journal of Inherited Metabolic Disease 22, no (May 1999): 263–66 Matalon, Reuben, and Kimberlee Michals-Matalon “Chemistry and Molecular Biology of Canavan Disease.” Neurochemical Research 24, no (April 1999): 507–13 Matalon, Reuben, and Kimberlee Michals-Matalon “Recent Advances in Canavan Disease.” Advances In Pediatrics 46 (1999): 493–506 Matalon, Reuben, Kimberlee Michals-Matalon, and Rajinder Kaul “Canavan Disease.” Handbook of Clinical Neurology 22, no 66 (1999): 661–69 Traeger, Evelyn, and Isabelle Rapin “The clinical course of Canavan disease.” Pediatric Neurology 18, no (1999): 207–12 Carbamazepine is an antiepileptic drug used to reduce or suppress seizures The medication is also commonly prescribed to relieve certain neurogenic pain such as trigeminal neuralgia This drug decreases abnormal electrical impulses through nerve cell pathways by inhibiting the activity of sodium channels in neurons Consequently, it blocks the repetitive impulses that trigger seizures In the United States, brand names for carbamazepine include Tegretol, Carbatrol, and Epitol This medication is classified into the following categories: anticonvulsant, antimanic, and antineuralgic Purpose ORGANIZATIONS Canavan Foundation 320 Central Park West, Suite 19D, New York, NY 10025 (212) 877-3945 Canavan Research Foundation Fairwood Professional Building, New Fairwood, CT 06812 (203) 746-2436 canavan_research@hotmail.com Due to its high efficacy, carbamazepine is in many cases a first-line treatment for epilepsy, and is also frequently prescribed to treat acute neuralgias such as trigeminal neuralgia Sometimes the drug is also used to improve bipolar disorder symptoms, especially during the manic phase of this disease Description National Foundation for Jewish Genetic Diseases, Inc 250 Park Ave., Suite 1000, New York, NY 10017 (212) 371-1030 National Tay-Sachs and Allied Diseases Association 2001 Beacon St., Suite 204, Brighton, MA 02135 (800) 906-8723 ntasd-Boston@worldnet.att.net WEBSITES American College of Medical Genetics Position Statement on Carrier Testing for Canavan Disease FASEB (January 1998) Matalon, Reuben “Canavan disease.” GeneClinics (20 July 1999) Matalon, Reuben and Kimberlee Michals-Matalon “Spongy Degeneration of the Brain, Canavan Disease: Biochemical and Molecular Findings.” Frontiers in Biosience (March 2000) McKusick, Victor A “Canavan disease.” OMIM—Online Mendelian Inheritance in Man (December 8, 1999) Carbamazepine is a lipid-soluble substance metabolized in the liver by enzymes of the P-450 family and therefore, its chronic administration may induce liver toxicity, especially in patients with reduced liver function In contrast, persons whose P-450 enzymes are very efficient and metabolize the drug rapidly tend to have decreased carbamazepine half-life and therefore, reduced efficacy of the medication The body slowly absorbs carbamazepine and the drug easily passes through the blood-brain barrier It is rapidly transported into the central nervous system (CNS), where it exerts a depressant effect Recommended dosage For treatment of seizures, the usual initial dose of carbamazepine for adults and children over 12 years of age is 200 milligrams, taken twice daily The prescribing physician may increase the dosage in weekly intervals until optimum seizure control is achieved Dosages generally not exceed a range of 1000–1200 milligrams (mg) per day For the treatment of trigeminal neuralgia, daily dosages usually range from 800–1200 mg per day during the stage of acute pain and 400–800 mg per day for preventative therapy Precautions Lisa Maria Andres, MS, CGC Rosalyn Carson-DeWitt, MD 186 S Carbamazepine The ingestion of alcoholic drinks during carbamazepine therapy is contraindicated because both substances may potentiate (increase) the effects of the other GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Epilepsy A disorder associated with disturbed electrical discharges in the central nervous system that cause seizures Neurogenic pain Pain originating in the nerves or nervous tissue Trigeminal neuralgia A disorder affecting the trigeminal nerve (the 5th cranial nerve), causing episodes of sudden, severe pain on one side of the face Other depressants of the central nervous system such as antihistamines, analgesic drugs, muscle relaxants, and tranquilizers, are also potentiated when used with carbamazepine or other antiepileptic medications Diabetic patients should be monitored during the administration of this drug since it interferes with glucose blood levels The drug should not be taken during pregnancy due to the absence of safety clinical studies for pregnant women Tests in animals have shown that carbamazepine causes developmental defects in embryos when administered in high doses As the drug is found in breast milk, the use of this medication is also contraindicated during breast-feeding Carbamazepine may interfere with several biomarkers used in medical laboratory tests, and persons taking the medication should report its intake before blood or urine samples are collected for analysis Side effects The intensity of side effects (or adverse effects) of carbamazepine is dose-dependant Among the mild adverse effects observed during chronic administration of this medication are drowsiness, vertigo, fatigue, blurred vision, gastritis, constipation, aching muscles or joints, skin sensitivity to solar radiation, loss of appetite, and dry mouth In most patients, these side effects are mild and tend to decrease in intensity or to completely disappear within a few days of treatment However, if they are particularly intense or persist for two or more weeks they should be reported to the physician Nevertheless, elderly patients or patients exhibiting one or more severe symptoms in association with carbamazepine intake such as chest pain, blurred vision, mental confusion or hallucinations, numbness, tachycardia, depression or marked mood changes, urinary retention or excessive diuresis, peripheral edema, severe diarrhea or vomiting, should report such symptoms to their physicians as soon as possible Interactions The use of carbamazepine reduces the effectiveness of oral contraceptives and also reduces the effects of corticosteroids The concomitant use of one of the following drugs inhibits the metabolism of carbamazepine, thereby decreasing its effectiveness: cimetidine, erythromycin, isoniazid, diltiazem, and propoxyphene Conversely, carbamazepine decreases the plasma levels of phenytoin, another antiepileptic drug Clarithromycin, an antibiotic, increases the blood levels of carbamazepine and thus, increases the risk of adverse effects The use of particular antidepressant medicines known as monoamine oxidase (MAO) inhibitors during carbamazepine therapy, or within the previous two weeks before initiating carbamazepine therapy may increase the risk of fever, severe high blood pressure, stroke, and convulsions Therefore, an interval of at least two weeks is recommended between the administration of these two classes of drugs Resources BOOKS Champe, Pamela C., and Richard A Harvey, eds Pharmacology, 2nd ed Philadelphia, PA: Lippincott Williams & Wilkins, 2000 OTHER “Carbamazepine.” Medline Plus National Library of Medicine (January 1, 2003) (March 20, 2004) National Institute of Neurological Disorders and Stroke NINDS Trigeminal Neuralgia Information Page (May 29, 2001) (March 20, 2004) ORGANIZATIONS Epilepsy Foundation 4351 Garden City Drive, Landover, MD 20785-7223 (800) 332-1000 National Institute of Neurological Disorders and Stroke P.O Box 5801, Bethesda, MD, 20892-2540 (301) 496-5751 or (800) 352-9424 GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 187 Carbamazepine Key Terms Moreover, immediate medical attention may be required in the presence of one or more of the following adverse effects: presence of blood in the urine or urine with a dark color, black tarry stools or pale stools, unusual bleeding or bruising, skin rashes, ulcers or white spots in the mouth or lips, chills and fever, shallow or uneasy breathing or wheezing chest, jaundice, arrhythmia, sudden blood pressure fall or unusual high blood pressure, cough and/or sore throat These side effects could indicate the presence of a potentially serious blood disorder Carotid endarterectomy contact_us.htm> or Sandra Galeotti S Carotid endarterectomy Definition Carotid endarterectomy is a surgical procedure to treat obstruction of the carotid artery caused by atherosclerotic plaque formation Purpose The purpose of surgical therapy for vascular disease is to prevent stroke Stroke can be caused by atherosclerosis of the carotid arteries located in the neck Atherosclerosis is a degenerative disease of the cardiovascular system, which can occur in the carotid arteries in the neck, resulting in plaques of lipids, cholesterol crystals, and necrotic cells The plaques in the carotid arteries can result in disease by embolizing, thrombosing, or causing stenosis (narrowing of artery) The plaques in the carotid arteries can cause disease if they obstruct a vessel or get dislodged and obstruct another area Precautions The procedure is contraindicated in patients with an occluded carotid artery and in cases of severe neurologic deficit resulting from cerebral infarction Additionally, the procedure is not performed in persons with concurrent medical illness severe enough to limit life expectancy During the operation, precautions should be taken to prevent intraoperation movement of the atherosclerotic plaque This can occur by excessive manipulation of the carotid bifurcation (the anatomical point where the internal and external carotid is joined together) The internal carotid will extend from the neck and penetrate the brain (to provide the brain with blood), whereas the external carotid will form other smaller arteries to provide blood to structures within the neck region Atherosclerotic plaques are fragile especially if they are ulcerated During the operation the surgeon must carefully dissect free other attached vessels such as the common carotid, internal carotid, and external carotid arteries with minimal physical manipulation of the affected carotid vessel Description The first successful carotid endarterectomy was performed by DeBakey in 1953 During the past 40 years the procedure has been optimized and has become the most 188 frequently performed peripheral vascular operation in the United States There are more than 130,000 cases of carotid endarterectomy performed annually in the United States Several randomized prospective clinical trials have conclusively established both the safety and efficacy of carotid endarterectomy and its superiority for favorable outcomes when compared to the best medical management Largely due to credible scientific and clinical research, there has been a very large increase in the performance of this procedure over the past ten years It is understandable that the procedure is common since it is utilized for the treatment of stroke, which is a condition that is associated with high morbidity (death rates) and is frequent Carotid endarterectomy is the most common surgical procedure in the United States utilized to treat stenosis (narrowing) of the carotid artery There are approximately more than 700,000 incident strokes annually and 4.4 million stroke survivors There are 150,000 annual deaths from stroke Approximately 30% of stroke survivors die within the first 12 months Within 12 years approximately 66% will eventually die from stroke, making this condition the third leading cause of death in the United States The cause of atherosclerosis is unknown, but injury to the arteries can occur from infectious agents, hyperlipidemia, cigarette smoking, and hypertension The aggregate cost associated with approximately 400,000 first strokes in 1990 was $40.6 billion Among those who have experienced one stroke, the incidence of stroke within five years is 40–50% Research as of 2002 concludes that carotid endarterectomy remains the standard of care for the treatment of carotid artery atherosclerosis Surgical Description A vertical incision is made in front of the sternocleidomastoid muscle providing optimal exposure of the surgical field The line of the incision (10 cm in length) begins at the mastoid process and extends to approximately one to two fingerbreadths above the sternal notch The exact location of carotid bifurcation can be determined before operation by ultrasound studies or arteriography Muscles and nerves within the area are carefully displaced to allow access to the diseased area (plaque) When the surgical field is cleared of adjacent anatomical structures the endarterectomy portion of the procedure is carried out This is accomplished by an incision in the common carotid artery at the site below the atherosclerotic plaque The surgeon then uses an angled scissor (called a Potts scissor) to incise the common carotid artery through the plaque into the normal internal carotid artery It is vital to extend the arterial incision (arteriotomy) above and below the atherosclerotic plaque The surgeon utilizes a blunt dissecting instrument called a Penfield instrument to dissect the atherosclerotic plaque from the attachment to the arterial wall GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS After removing the atherosclerotic plaque, primary closure with sutures, or closure with a vein or prosthetic patch, is performed Research indicates that utilization of a prosthetic patch is more favorable than suture closing During this stage of the operation flushing is important to remove debris and air Vein patch is advantageous because this type of closure reduces the risk of thrombus accumulation and possibly prevents perioperative stroke the patient’s blood should be tested (complete blood count and electrolytes) Cardiac function can be monitored with ECG recordings Frequent neurologic assessment is essential as well as hemodynamic monitoring (with the goal of maintaining blood pressure at its prior range) The patient should be observed for hemotoma formation which could cause airway obstruction Antiplatelet therapy is necessary About two weeks postoperatively patients are evaluated for neurologic and wound complications Carotid ultrasound studies are performed after six months postoperatively and annually scheduled Preparation As part of the preoperative preparation, routine laboratory tests for blood chemistry (complete blood count, electrolytes), kidney function tests, lipid profiles, and special blood tests to monitor clotting times are ordered by the clinician Measurement of clotting times is important because blood thinner medications are typically given to patients preoperatively Neuroimaging studies of the head are important in symptomatic patients to identify old or new cerebral infarcts Carotid ultrasound studies are the screening test of choice accepted by surgeons to evaluate for carotid stenosis An electrocardiogram (ECG) is important for evaluating past myocardial infarction and ischemic cardiac changes The importance of ECG monitoring cannot be overemphasized given that the most common cause of postoperative mortality (death) is cardiac arrest Positioning of the patient is also important The operating table should be horizontal without head elevation The head should be partially turned to the opposite side of the surgical field It may be advantageous to place a rolled towel under the patient’s shoulders to exaggerate neck extension Gentle preparation and cleaning of operative fields should ensure minimal physical manipulation and pressure to avoid dislodging fragments of atherosclerotic plaque The goals for anesthetic management include control of blood pressure and heart rate, protection of the brain and heart from ischemic insult, and relief of surgical pain and operative stress responses Routine monitors (ECG and pulse oximetry to measure blood oxygen levels) and oxygen face mask are placed prior to anesthetic induction Typically, any commonly utilized anesthetic and muscle relaxants (nondepolarizing) can be administered for carotid endarterectomy Aftercare Aspirin therapy should be initiated at the time of diagnosis of transient ischemic attack (TIA), amaurosis fugax (transient visual loss), or stroke Recent research from the prospective Aspirin and Carotid Endarterectomy (ACE) trial suggests that low dose (80 to 325 mg per day) of aspirin is optimal in preventing thromboembolic events after carotid endarterectomy After carotid endarterectomy Risks There are several important complications that can occur after carotid endarterectomy Stroke or transient neurologic deficit can occur within 12 to 24 hours after operation These conditions are usually caused by thromboembolic complications, which typically originate from the endarterectomy site or damaged vessels that were involved during the operative procedure (internal, common, and external carotid arteries) In approximately 33–50% of patients, hypertension or hypotension can occur Wound complications such as hemotoma formation can cause pain and tracheal (wind pipe) deviation, which can impair normal breathing During surgery, damage to vital nerves can occur, such as cervical nerves which supply sensation to the neck region Patients may complain of numbness in the lower ear, lower neck, and upper face regions Damage to the hypoglossal nerve (which provides innervations of the tongue), can produce deviation of the tongue to the paralyzed side and speech impairment Additionally, the problem can reoccur, resulting in stenosis and symptoms Normal results The normal progression of results following carotid endarterectomy is the prevention of stroke which is approximately 1.6% (two-year stroke risk), compared to 12.2% for patients who are medically treated The results of the Asymptomatic Carotid Atherosclerosis Study (ACAS) reveal that the incidence of stroke for the postsurgical group (those receiving carotid endarterectomy) was 5.1%; for the group treated medically, the incidence was 11% As with all surgical procedures, it is important for patients to select a surgeon who has expertise in the particular procedure and in the management of the condition Some studies indicate that surgeons should perform 10 to 12 carotid endarterectomies every year in order to maintain surgical expertise and management skills Resources BOOKS Miller, Ronald D., et al, eds Anesthesia 5th ed Churchill Living Stone, Inc 2000 GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 189 Carotid endarterectomy Arterial Reconstruction Carotid endarterectomy Carotid endarterectomy (Custom Medical Stock Photo Reproduced by permission.) Key Terms Atherosclerotic plaque A deposit of fatty and calcium substances that accumulate in the lining of the artery wall, restricting blood flow Cerebral infarction Brain tissue damage caused by interrupted flow of oxygen to the brain Electrolytes Salts and minerals that produce electrically charged particles (ions) in body fluids Common human electrolytes are sodium chloride, potassium, calcium, and sodium bicarbonate Electrolytes control the fluid balance of the body and are important in muscle contraction, energy generation, and almost all major biochemical reactions in the body Hyperlipidemia A condition characterized by abnormally high levels of lipids in blood plasma Hypertension Abnormally high arterial blood pressure that if left untreated can lead to heart disease and stroke Mastoid process The protrusions of bone behind the ears at the base of the skull 190 Myocardial infarction Commonly known as a heart attack, a myocardial infarction is an episode in which some of the heart’s blood supply is severely cut off or restricted, causing the heart muscle to suffer and die from lack of oxygen Sternocleidomastoid muscle A muscle located in front of the neck that functions to turn the head from side to side Stroke Interruption of blood flow to a part of the brain with consequent brain damage A stroke may be caused by a blood clot or by hemorrhage due to a burst blood vessel Also known as a cerebrovascular accident Transient ischemic attack A brief interruption of the blood supply to part of the brain that causes a temporary impairment of vision, speech, or movement Usually, the episode lasts for just a few moments, but it may be a warning sign for a full-scale stroke GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS PERIODICALS Barnett, Henry J M “The appropriate use of carotid endarterectomy.” Canadian Medical Association Journal 166 (April 2002): Gross, Cary, P “Relation between prepublication release of clinical trial results and the practice of carotid endarterectomy.” Journal of the American Medical Association 284 (December 2000): 22 Mullenix, Philip “Carotid Endarterectomy remains the gold standard.” American Journal of Surgery 183, no 59 (May 2002) Perler, Bruce A “Carotid Endarterectomy: The ‘gold standard’ in the endovascular era.” Journal of the American College of Surgeons 194, no (January 2002) Walker, Paul M “Carotid Endarterectomy: applying trial results in clinical practice.” Canadian Medical Association Journal 157 (1997) ORGANIZATIONS National Stroke Association 9707 E Easter Lane, Englewood, Colarado 80112 303-649-9299 or 1-800-strokes; Fax: 303-649-1328 Laith Farid Gulli, M.D Robert Ramirez, D.O S Carotid stenosis Definition Carotid stenosis is the medical description of the narrowing or constriction of the carotid artery The artery is located in the neck, and the narrowing of the artery is caused by the buildup of plaque (fatty deposits) The process of atherosclerosis causes a hardening of the walls of the arteries and, in the case of atherosclerosis in the carotid artery, results in a carotid stenosis that reduces the flow of blood and nutrients to the brain Description blood flow This blockage interrupts the supply of nutrients and oxygen to the brain, and is one of the causes of cerebral vascular accidents, known as stroke Carotid stenosis is a form of cerebral vascular disease and atherosclerosis Demographics Stroke is the third leading cause of death in the United States after coronary artery disease and cancer, with approximately 750,000 strokes and more than 150,000 deaths occurring each year in the United States Approximately 50% of these strokes are thought to be the result of carotid stenosis Causes and symptoms The cause of carotid stenosis is the buildup of plaque on the inner wall of the carotid artery The reduced blood flow to the brain and the blockage of other arteries following the release of emboli can cause a stroke Increased risk of carotid stenosis is associated with smoking, hypertension, elevated levels of cholesterol, obesity, and a sedentary lifestyle Some of these factors such as hypertension and cholesterol level may also be related to a person’s physiology Another risk factor is diabetes Older, less active people are more prone to carotid stenosis Additionally, the older a person is, the greater the risk posed by carotid stenosis Sometimes, prior to a major stroke, a person can be temporarily affected by the arterial blockage or release of a small embolus The interrupted flow of blood to the brain, which can be very brief or last a few hours, does not persist longer than 24 hours Symptoms of this transient event, called a transient ischemic attack (TIA), include weakness, as well as visual and speech difficulties The exact symptoms of carotid stenosis depend on the area of the brain that is affected Symptoms can also be absent, with the stenosis discovered only incidentally during a clinical examination In the event of a stroke, if the blocked blood flow is not restored, brain cells can die, causing permanent brain damage The carotid arteries run up the sides of the neck They are vital arteries, and are a route of blood to the anterior part of the brain and, via branches, to the eyes, forehead, and nose The deposition of plaque along the inner wall of an artery narrows its diameter This makes the clogged artery less efficient in transporting blood Plaque formation can become so severe that an artery is effectively blocked Although not as accurate as other methods, a physician can listen to the pulsing of blood through the carotid artery by means of a stethoscope The weaker pulse that is a result of stenosis will be evident in the form of altered sounds (bruits) as the blood flows past the area of disturbance Carotid stenosis poses another danger when bits of the plaque dislodge These pieces, which are referred to as blood clots or emboli, can move upward with the flow of blood towards the brain and can become lodged, blocking Sometimes, carotid stenosis is suspected if a person has a transient malfunction of blood flow to the brain, or a TIA A TIA can last anywhere from a few seconds to several hours The temporary blockage of the artery can Diagnosis GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 191 Carotid stenosis Townsend, Courtney M Sabiston Textbook of Surgery 16th ed W B Saunders Company, 2001 Carotid stenosis Key Terms Carotid endarterectomy Surgical procedure designed to reduce the accumulation of plaque in the carotid artery and thus prevent stroke Cerebral vascular accident Damage to brain cells caused by lack of blood flow in the brain from emboli (clots) plaque, or hemorrhage Stenosis Narrowing or constriction of a blood vessel or passage in the body The third technique is known as an angiogram or arteriogram An angiogram is an examination that utilizes x rays after a small tube (catheter) is inserted into the base of the carotid artery An x-ray dye is then injected The dye reveals the areas of the regions of the artery that are narrowed or blocked Treatment team Diagnosis and treatment of carotid stenosis involves the primary care physician, nurses, neurologist, neurosurgeons, neuroradiologists, and specialists who are skilled in performing angioplasty Treatment False-color angiogram showing stenosis in the carotid artery (Photograph by Alfred Pasteka (c) CNRI/ Science Photo Library, National Audubon Society Collection/Photo Researchers, Inc Reproduced by permission.) Carotid stenosis is treated surgically or medically One of two surgical treatments is typically used The first approach is known as microsurgical carotid endarterectomy The second approach is termed endovascular angioplasty and stenting cause a momentary loss of vision in one eye, a weak or numb sensation on one side of the body, slurred speech, or inability to speak A TIA can be a warning to a physician of the potential presence of carotid stenosis Carotid endarterectomy is the surgical exposure of the carotid artery and the removal of the plaque This re-establishes the uninterrupted flow of blood to the brain This approach is the method of choice for most patients However, the technique does itself carry a risk of stroke (stroke can be caused in up to 3% of surgeries) Three main diagnostic tests aid in the diagnosis of carotid stenosis The first is known as a duplex sonogram, or a carotid duplex The procedure involves the use of highfrequency sound waves (ultrasound) The ultrasonic waves echo off of the carotid artery to produce a two-dimensional image on a monitor If narrowing or obstruction of the carotid artery is present, it is often apparent in the image Another powerful imaging technique is magnetic resonance imaging (MRI) or magnetic resonance angiography (MRA) Both rely on the use of magnetism Pulses of magnetic energy can be used to image the targeted area of the body, based on the interruption of the flow of the electrons in the magnetic field This information is then converted to a visual image 192 For patients who are unable to undergo surgery, the angioplasty and stenting approach is used In this approach a catheter that contains an expandable region at one end is inserted into the carotid artery The end of the catheter is then expanded This “balloon” squeezes the plaque against the arterial wall, increasing the effective diameter of the artery Then, a stent is placed inside the artery A stent is a tubular arrangement of fibers somewhat similar visually to wire fencing rolled up into a tube The stent reinforces the carotid artery to prevent its collapse and to keep the plaque tightly against the arterial wall Surgery and the associated risks may not be warranted in patients whose arterial blockage is less than 50% GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS Resources BOOKS Wiebers, David Stroke-Free for Life: The Complete Guide to Stroke Prevention and Treatment 2nd ed Mayo Clinic New York: Harper Resource, 2002 PERIODICALS Clinical trials As of February 2004, a clinical trial designed to investigate the relative effectiveness of carotid angioplasty with stenting versus carotid endarterectomy in preventing stroke, myocardial infarction, and death was recruiting patients in the United States and Canada Participants should have symptoms of carotid stenosis The trial, called “Carotid Revascularization Endarterectomy versus Stent Trial (CREST),” was being coordinated by the National Institute for Neurological Diseases and Stroke Another clinical trial was designed to examine the role of diet (specifically high doses of vitamin E) on the metabolism of low-density lipoprotein, which is critical in plaque formation This trial was being coordinated by the National Institute of Health’s National Center for Complimentary and Alternative Medicine Information on both clinical trials may be found at the National Institute of Health Clinical Trials website: www.clinicaltrials.gov Prognosis With prompt medical treatment, including surgery, recovery from carotid stenosis can be complete with no residual effects However, if treatment is delayed or if a stroke occurs, damage can be permanent If carotid stenosis is dealt with promptly by surgery, medicine, or lifestyle modifications, prognosis is good For example, at the Johns Hopkins Medical School, carotid stenosis corrective surgery has a mortality rate of 0.8% (80 in 1,000 people) and a morbidity rate (the person survives, but with some complication) of 1.8% (18 in 1,000 people) However, undiagnosed stenosis can result in stroke Depending on the severity of the stroke, prognosis is variable An estimated 325,000 strokes and 75,000 deaths occur each year in the United States due to carotid stenosis Special concerns Even if there are no symptoms associated with the presence of carotid stenosis, the malady is often a warning sign of possible blockage of the arteries of the heart, or coronary artery disease Thus, people diagnosed with carotid stenosis should be carefully monitored for coronary artery disease Biller, J., and W H Thies “When to operate in carotid artery disease.” American Family Physician (January 2000): 400–406 OTHER Johns Hopkins Department of Neurosurgery “What is Carotid Stenosis?” Johns Hopkins University School of Medicine (February 1, 2004). “Risk Reduction through Surgery: Carotid Endarterectomy.” National Stroke Association (March 1, 2004) Toronto Brain Vascular Malformation Study Group “Carotid Stenosis What is Carotid Stenosis?” University of Toronto (February 1, 2004). ORGANIZATIONS American Stroke Association, a division of the American Heart Association 7272 Greenville Avenue, Dallas, TX 75231 (888) 4-STROKE Centers for Disease Control and Prevention (CDC) 1600 Clifton Road, Atlanta, GA 30333 (404) 639-3311 or (800) 311-3435 National Institute for Neurological Diseases and Stroke (NINDS) 6001 Executive Boulevard, Bethesda, MD 20892 (301) 496-5751 or (800) 352-9424 Brian Douglas Hoyle, PhD S Carpal tunnel syndrome Definition Carpal tunnel syndrome is an entrapment neuropathy of the wrist It occurs when the median nerve, which runs through the wrist and enervates the thumb, pointer finger, middle finger and the thumb side of the ring finger, is aggravated because of compression Symptoms include numbness, tingling and pain in the fingers the median nerve sensitizes Some people have difficulty grasping items and may have pain radiating up the arm Carpal tunnel syndrome is common in people who work on assembly lines, doing heavy lifting and packing involving repetitive motions Other repetitive movements such as GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 193 Carpal tunnel syndrome Anticoagulant medications such as aspirin can be used instead to reduce the tendency of blood clots to form Treatment can also consist of lifestyle modifications such as stopping smoking, limiting cholesterol intake, or use of cholesterol-lowering medications Carpal tunnel syndrome typing; are often implicated in cause carpal tunnel syndrome, however some clinical evidence contradicts this association Additional causes of the syndrome include pregnancy, diabetes, obesity or simply wrist anatomy in which the carpal tunnel is narrow Treatment includes immobilization with a splint or in severe cases surgery to release the compression of the median nerve Description Carpal tunnel syndrome (CTS) is caused by a compression of the median nerve in the wrist, a condition known as nerve entrapment Nerve entrapments occur when a nerve that travels through a passage between bones and cartilage becomes irritated because a hard edge presses against it In almost every case of nerve entrapment, one side of the passage is moveable and the repetitive rubbing exacerbates the injury Three sides of the carpal tunnel are made up of three bones that form a semicircle around the back of the wrist The fourth side of the carpal tunnel is made up of the transverse carpal tunnel ligament also called the palmar carpal ligament, which runs across the wrist on the same side as the palm This ligament is made of tissue that cannot stretch or contract, making the cross sectional area of the carpal tunnel a fixed size Running through the carpal tunnel are nine tendons that assist the muscles that move the hand and the median nerve The median nerve enervates the thumb, forefinger, middle finger, and the thumb side of the ring finger The ulnar nerve that serves the little finger side of the ring finger and the little finger runs outside of the transverse carpal tunnel ligament and is therefore less likely to become entrapped in the wrist The tendons that run through the carpal tunnel are encased in a lubricating substance called tensynovium This substance can become swollen when the tendons rub quickly against one another, as occurs when the finger muscles are used repeatedly When this happens, there is less space within the carpal tunnel for the median nerve and it becomes compressed or pinched When a nerve is compressed, the blood supply to the nerve is interrupted In an attempt to alleviate the problem, the body’s immune system sends new cells called fibroblasts to the area to try to build new tissue This eventually results in scar tissue around the nerve In an area that cannot expand this only worsens the situation and puts more pressure on the nerve A compressed nerve can be likened to an electrical wire that has been crimped It cannot transmit electrical signals to the brain properly and the result is a feeling of numbness, tingling or pain in the areas that the nerve enervates Compression of the median nerve causes tingling and numbness in the thumb, forefinger, middle finger and on 194 Key Terms Median nerve A nerve that runs through the wrist and into the hand It provides sensation and some movement to the hand, the thumb, the index finger, the middle finger, and half of the ring finger Neuropathy A disease or abnormality of the peripheral nerves (the nerves outside the brain and spinal cord) Major symptoms include weakness, numbness, paralysis, or pain in the affected area the thumb-side of the fourth finger It may also cause pain in the forearm and occasionally into the shoulder Some persons have a difficult time gripping and making a fist People who suffer from CTS range from those who are mildly inconvenienced and must wear a splint at night to relieve pressure on the median nerve to those who are severely debilitated and lose use of their hands Problems associated with CTS can invade a person’s life making even simple tasks such as answering the phone, reading a book or opening a door extremely difficult In severe cases, surgery to release the median nerve is often suggested by an orthopedist The carpal tunnel ligament is cut, relieving the pressure within the carpal tunnel Rates of success are quite high with the surgical procedure Demographics Carpal tunnel syndrome is more common in women than in men, perhaps because the carpal tunnel generally has a smaller cross section in women than in men The ratio of women to men who suffer from CTS is about three to one CTS is most often diagnosed in people who are between 30 and 50 years old It is more likely to occur in people whose professions require heavy lifting and repetitive movements of the hands such as manufacturing, packing, cleaning and finishing work on textiles Causes and symptoms Carpal tunnel syndrome may occur when anything causes the size of the carpal tunnel to decreases or when anything puts pressure on the median nerve Often the cause is simply the result of an individual’s anatomy; some people have smaller carpal tunnels than others Trauma or injury to the wrist, such as bone breakage or dislocation can cause CTS if the carpal tunnel is narrowed either by the new position of the bones or by associated swelling Development of a cyst or tumor in the carpal tunnel will also result in increased pressure on the median nerve and likely CTS Systemic problems that result in swelling may GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS ... Association 919 North Michigan Avenue, Suite 11 00, Chicago, IL 60 611 -1 6 76 ( 312 ) 33 5-8 700 or (800) GALE ENCYCLOPEDIA OF NEUROLOGICAL DISORDERS 15 5 Biopsy 27 2-3 900; Fax: ( 312 ) 335 -1 1 10 info@alz.org... ( 41 5 ) 43 4- 3 388 or (800) 44 5- 810 6; Fax: ( 41 5 ) 43 4- 3 508 info@caregiver.org National Institute of Neurological Disorders and Stroke (NINDS) at the National Institutes of. .. 34 0-9 918 Fax: ( 215 ) 340 918 1 The Society of Teachers of the Alexander Technique The Trager Institute 21 Locust Avenue, Mill Valley, CA 949 4 1- 2806 ( 41 5 ) 38 8-2 688